This invention generally relates to duplex printing. More particularly, this invention relates to a method for a duplexing image forming device which automatically generates a second side image for a sheet of media.
Oftentimes when documents are sealed in an envelope, it is desired that the contents remain confidential until the envelope is opened. Special paper and/or security envelopes are used to prevent the envelope contents from being read by illuminating the envelope from the opposite side. In the same vein, financial information is often printed on special forms which include opaque areas to prevent the transmission of light. This requires the confidential information to be printed at pre-defined areas on the form and therefore follow a specific format. Obviously, in any of these cases, there is additional expense and effort expended to protect the information.
An additional problem, which at first blush seems unrelated, has to do with reusing single sided printed pages for generating draft documents. The problem arises in trying to distinguish between the prior printed material and the newly printed material. When printing appears on just one side of a series of printed pages there is no possibility for confusion. However, when a new print job is printed on the blank side of previously printed pages it becomes difficult to tell which is which.
It would be desirable to provide a method for protecting confidential information using standard paper and envelopes and a method to distinguish between previously printed sides of a multi-page document and the newly printed sides.
The invention uses a duplex printer to print indicia on the back side of a printed page to provide privacy for confidential information appearing on the front side and indicia to indicate that information which previously appeared on the back side of a printed sheet is not relevant to the information appearing on the front side of the printed sheet.
The invention can be implemented in several different embodiments which include a software implementation in either the application software on the host device or in the printer driver on the host device. Or, the invention can be implemented in firmware within the image forming device. In either case, it is advantageous that the image forming device have duplexing capability so that the user does not have to xe2x80x9cre-runxe2x80x9d the print job to print on both sides of the pages.
In the privacy mode, the invention identifies privacy zones within the original document and then maps these zones to the reverse side of the sheet using a mirror image mapping technique. The privacy zones can be designated manually by the user through a graphical user interface or automatically using imbedded codes such as a privacy font. In the case of the privacy font type implementation, the invention generates the privacy zones by demarcating the particular text within an area on the printed page within which the text resides. The location, size and shape of the zones is then mimicked in mirror image fashion on the reverse side of the printed sheet and these zones are filled with obscuring indicia to block the transmission of light and thereby protect the confidentiality of the information.
In the single side paper reuse mode, the invention prints indicia on the reverse side of the printed sheets which indicates that the information contained on the reverse side is not relevant to the printed document. This information may take the form of text, graphics, lines, etc. In one embodiment, diagonal lines are used across the entire back side of the page similar to the denotation of a cross section part in a mechanical drawing.